The invention relates generally to beam splitters, and in particular, to a compact beam splitter apparatus for use with a surface wave acousto-optic time integrating correlator.
In known acousto-optic time integrating correlators, such as the correlator described in U.S. Pat. No. 4,326,778, issued Apr. 27, 1982 to Berg et al, or the correlator described in the U.S. Pat. No. 4,421,388 issued Dec. 20, 1983 to Berg et al, two beams generated from a single laser converge on an acousto-optic delay line with a small angle between the two beams. In these known correlators, a beam splitter and a mirror are used to form these two converging light beams. Generally, the angle between these two light beams must be very small; consequently, a long light path length is required between the beam splitter or mirror and the acousto-optic delay line.